function Animal() {
    this.species = '动物';
}

function Cat(name,color) {
    // Animal.apply(this,arguments);
    this.name = name;
    this.color = color;
}
// prototype模式
// let ani = new Animal();
Cat.prototype = new Animal();  -  
Cat.prototype.constructor=Cat;
let cat1 =new Cat('大毛','黄色');
console.log(cat1.species);
console.log(Cat.prototype.constructor);